1166598661 has 4 divisors (see below), whose sum is σ = 1173755872. Its totient is φ = 1159441452.

The previous prime is 1166598659. The next prime is 1166598677. The reversal of 1166598661 is 1668956611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1166598661 - 2¹ = 1166598659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166598691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3578361 + ... + 3578686.

It is an arithmetic number, because the mean of its divisors is an integer number (293438968).

Almost surely, 2^1166598661 is an apocalyptic number.

It is an amenable number.

1166598661 is a deficient number, since it is larger than the sum of its proper divisors (7157211).

1166598661 is an equidigital number, since it uses as much as digits as its factorization.

1166598661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7157210.

The product of its digits is 466560, while the sum is 49.

The square root of 1166598661 is about 34155.5070376652. The cubic root of 1166598661 is about 1052.7061445336.

The spelling of 1166598661 in words is "one billion, one hundred sixty-six million, five hundred ninety-eight thousand, six hundred sixty-one".